Viewing Memory Usage

About Memory Usage in Linux

Linux will utilize unused memory on the system for caching files and other data. This is by design and is done to improve system performance. You may see that your server has low "free" memory, but as long as it still has "available" memory, this is not a cause for concern.

You can check memory usage on any Linux system with the free -h command. For example:

# free -h
              total        used        free      shared  buff/cache   available
Mem:           31Gi       8.2Gi       1.9Gi        91Mi        20Gi        22Gi
Swap:         7.6Gi       596Mi       7.0Gi

In the above example, the system has only 1.9 GB of free memory, but most of that is cached, marked as buff/cache. The available memory is 22 GB, which is how much memory is actually available for use by applications. As long as the system has available memory, having low free memory is not a cause for concern.